<!DOCTYPE html>
Tests painting of fixed background content in scrolled container.
Passes if the background doesn't scroll.
<div style="position: absolute; top: 100px; left: 100px; width: 400px; height: 400px; backface-visibility: hidden">
  <iframe style="width: 300px; height: 300px" srcdoc="
    <style>
    ::-webkit-scrollbar {
      display: none;
    }
    </style>
    <div id='container' style='width: 200px; height: 200px; overflow: scroll'>
      <div id='content' style='height: 2000px; background: linear-gradient(red, blue); background-attachment: fixed'></div>
    </div>
  "></iframe>
</div>
